Sealing closure



H. Q. BAIR SEALING CLOSURE Dec. 29, 1964 Filed April 9, 1962 INVENTOR. HERBERT Q. BAIR Y FIG. 2

United States 3,162,917 Patented Dec. 29, 1964 ice 3,162,917 SEALiNG CLfiSURE Herbert Q. Bair, Tailmadge, Ohio, assigns: to The B. F. Goodrich Company, New York, N.Y., a corporation of New York Filed Apr. 9, 1962, Ser. No. 186,249 3 Claims. (Cl. 2420S.1)

This invention relates to a sealing closure of the type employing a plurality of opposed series of interlocking fastener elements provided with cooperating lips of elastomeric material over which elements and lips a slider operates to selectively efiect opening or closing of the fastener. More particularly, the invention relates to a fastener of this type wherein the surfaces of the sealing lips, which are contacted by the slider, provide less frictional resistance to movement of the slider than in conventional closures of this'type.

Closures of the type'to which this invention pertains are capable of providing a fluid-tight seal over the separable fastener elements through action of the sealing lips engaging each other when the slider is operated in the direction to effect closure. However, this sealing action requires that the lips, which provide the scaling function, be formed of flexible elastomeric material sufficiently soft to readily conform to each other even though the closure and the margins to which it is attached are flexed in a plurality of different directions. Unfortunately, the soft nature of lips which provide adequate scaling for such separable closures have also caused considerable frictional drag to the movement of the slider which effects closure operations. This frictional drag not only makes opening and closing operations difficult but may even result in damage to the sealing lips.

In accordance with this invention, resistance to move ment of the closure actuating slider thereover is materially reduced by modifying the area of the lips which are contacted by the slider without, however, altering the nature of the portions of the lips which interengage each other in sealing engagement. In one embodiment of the invention, the modification is effected by reducing the area of contact between the slider and lips through providing the surface of the lips contacted by the slider with alarge number of small area depressions. In another embodiment of the invention, the surface contacted by the slider is chemically modified to reduce its coefficient of friction. In a still different embodiment, the surface modification includes a combination of both reduction in area of contact and chemical modification of the contacting area. In all embodiments of the invention, however, the modification of the surfaces of the sealing lips contacted by the slider'is exclusive of the portions of these lips which engage each other in sealing contact so that fluid-tight sealing of the closure is not impaired.

Other features and advantages of the invention will be apparent from the following detailed description of the presently preferred embodiment, and modifications thereof, described with reference to the accompanying drawing, forming a part of this application, and in which:

FIG. 1 is a fragmentary perspective view of a sealing closure in partly open condition showing the presently preferred embodiment of the invention; and

FIG. 2 is a view similar to FIG. 1 but to a smaller scale showing a modification of the invention.

The sealing closure is shown in FIG. 1 of the drawing as it is employed to unite the margins 1d and 11 of flexible material. This fastener comprises the usual series of spaced apart interlocking fastener elements 12 and 13 attached to the opposed edges of the margins 11) and 11 or to tapes or stringers which are attached to those margins. The fastener elements 12 and 13 are also provided with longitudinally extending sealing lips 14 and 15 of elastomeric material which have adjacent edges adapted to overlap in sealing relationship, as shown at 16 in FIG. 1, when the fastener elements 12 and 13 are in locking engagement.

The sealing lips 14, 15 have the portions thereof remote from the interengaging edges 16 secured, respectively, to one face of the rear portions of the interlocking fastener elements 12 and 13, and to the adjacent'portions of the tapes or margins 10 and 11 on which the elements are provided, which tapes or margins may likewise be covered with elastomeric material. This construction is conventional and selectively effects sealing closure or opening between the margins 10 and 11 by longitudinal movement along the fastener elements 12 and 13 and sealing lips 14 and 15 of a runner or slider 17. This runner or slider 17 comprises a pair of interconnected spaced plate-like portions 18 and 19 respectively contacting the fastener elements 12, 13 and the sealing lips 14, 15.

In acordance with this invention the areas of the sealing lips 14, 15 which are contacted by the slider 17 as it moves 7 thereover are modified to reduce the frictional resistance of these surfaces to such movement of the slider. This surface modification may extend laterally beyond the regions in contact with the slider into the adjacent areas of the margin portions 113 and 11 but does not extend laterally inwardly on the sealing lips onto the surfaces of the edge portions thereof which contact each other in sealing relationship. In this regard, it is tobe noted that While the entire outer surface of the lip 14 may be so surface modified, the portion of the outer surface of the cooperating lip 15 which is overlapped by the adjacent portion of the lip 14 should not be so modified nor should the adjacent inner surface of the lip 14 be thus modified. The surface modification may comprise a reduction in the area of the surfaces normally contacted by the slider as, for example, by forming a plurality of small area depressions therein, chemical modification of the surface to re duce the coefficient of'friction thereof, or by a combination of both treatments.

The preferred embodiment of the invention has the surfaces of the sealing lips 14, 15, which are engaged by the slider 17, both chemically modified to reduce their coelficient of friction and also provided with a plurality of small area depressions to reduce the total area of surface contacting the slider. The chemical modification is preferably effected by chlorination of the surfaces in question which may be effected by expedients known in the rubber compounding art. For example, a chlorine solution may be applied for a predetermined time to the surfaces In addition to the chemical modification of the surfaces of the lips 14 and 15 contacted by the slider these surfaces are also mechanically modified by creating small area depressions therein as indicated by the stippling in FIG. 1. These small area depressions can be produced by a variety of operations but preferably are formed during the operation of molding the sealing lips'upon the margins 10 and 11, the desired depressions being formed during this operation by roughening of the appropriate areas of the mold. This roughening can be effected, for example, by sandblasting, knurling, by placing a rough surfaced fabric in the mold to contact the elastomeric material during molding, or by other known expedients. If desired, still further reduction of resistance to movement of the slider can be achieved by applying suitable known lubricants to the surfaces of the sealing lips contacted by the slider..

The small area depressions are of further assistance when a lubricant is used by aiding in retention of the lubricant at the proper location.

Maximum improvement in reduction of frictional resistance to movement of the slider 17 is accomplished by a surface modification embodying chemical modification of the surface of the elastomer, mechanical modification and use of a lubricant as described above. However, significant improvement in reduction of frictional resistance can also be achieved by either of the surface modifications alone orwith a lubricant.

with this invention, solely by chemical modification of the surfaces of the sealing lips.

This closure, as shown in FIG. 2, selectively efiects sealing closure of the margins 2th and 21 through selective engagement or disengagement of the fastener elements 22 and 23 and the selective overlapping or separation of I the elastomeric sealing lips 24 and 25 through operation of the slider 26 in the manner which will be readily apparent. The operation of thevslider is, facilitated by chemical modification of those surfaces of the sealing lips 24 and 25 which are contacted by the slider'ild to reduce their surface tack. This preferably is efiectecl by chlorinating the surfaces in question in the same manner as has been described above'with respect to the embodiment illustrated in FIG. 1. However, in this instance, the surfaces of the sealing lips which have been modified by the chemical treatment are not additionally mechanically modified by providing small dimension depressions ther in. Nevertheless, it has been found that reduction of frictional resistance to movement of the slider as is significantly improved by the treatment.

It'has also been found that reduction in frictional r sistance of the movement of the slider of a sealingjclo- Thus,.a sealing closure of im- 7 proved nature and operation is provided, in accordance Having thus described the invention, I claim: 1. Ina sealing closure for uniting in sealing relationship margins of a flexible material wherein the said closure comprises an opposed series of spaced apart inter locking fastener elements attached to said margins, a pair of flexible sealing lips of elastomeric material attached to said margins and adapted to extend in overlapping engagement with each other over one face of the said elements when the latter are engaged, and a slider comprising a pair of plate-like portions in contact, respectively, with said fastener elements and said lips, the improvement which comprises the elastomeric material in the area of contact with said slider being chlorinated while thefinterengaging portions of said lips are unchlorinated.

2. In a sealing closure for uniting-1'11 sealing relationship margins of a flexible materialwherein the said closure comprisesan opposed series'of spaced apart interlocking fastener'elements attached to said margins, a pair of flexible sealing lips of elastomeric material attached to said margins and adapted to extend in overlapping engagement with each other over one face of the said elements when the latter are engaged, and a slider comprising a pair of plate-like portions in'contact, respectively,

p with said fastener elements and said lips, the improvement which comprises the surfaces of said sealing lips contacted by'said slider being chlorinated and provided with a plurality of small area depressions below the level of the slider-contacting surfaces. 7

'3. A closure for uniting in sealing relationship margins of flexible material, the said closure comprising an opposed series of spaced apart interlocking fastener elements a attached to said margins, a pair of flexible sealing lips of elastomeric material attached to said margins and adapted to extend in overlapping engagement with each other over sure can be materially reduced solely by mechanical modification of the surface of the lips contacted by the slider; 'Thus, a sealing closure in which the surfaces of the sealing lips contacted by the slider were provided with small area depressions as shown in FIG. 1 evidenceda material reduction in the frictional resistance to slider operation as compared with sealing closures of'like nature *which did not have the surfaces of the sealing lips modifiedin' Further reduction of frictional resistance to this manner. slider operation Was achieved by applying a lubricant to the surfaces of the sealing lips contacted by the slider and one face of said elements when the latter are engaged, and a slider comprising a pair of plate-like portions in contact, respectively, with the said fastener elements and said lips, the surface of that portion of said sealing lips "i contacted by said slider containing'a plurality of small area depressions therein and the elastomer in which said small area depressions are located bein'g'chlorinated while when this was done the small area depressions assisted v in retention of the lubiicant'in proper location for a 'long-' er time thansealing closures without such surface modification. a

The invention has been described specifically as it is incorporated in the presently preferred embodiment and certain modifications thereof. c This specific description is, however, intended merely for purposes of complete explanation of the invention and is not to be construed as a limitation thereon since variations may be made within the spirit and scope of the appended claims,

the interengaging portions of said lips are unchlorinated.

' References Cited by tlie Examiner 7 8/54 Great Britain. I

M. HENSON woon, In.,Pr1 'niary Exqminer. a

I ABRAHAM G. STONE, DONLEY I STOCKING,

. a i Examiners. 

1. IN A SEALING CLOSURE FOR UNITING IN SEALING RELATIONSHIP MARGINS OF A FLEXIBLE MATERIAL WHEREIN THE SAID CLOSURE COMPRISES AN OPPOSED SERIES OF SPACED APART INTERLOCKING FASTENER ELEMENTS ATTACHED TO SAID MARGINS, A PAIR OF FLEXIBLE SEALING LIPS OF ELASTOMERIC MATERIAL ATTACHED TO SAID MARGINS AND ADAPTED TO EXTEND IN OVERLAPPING ENGAGEMENT WITH EACH OTHER OVER ONE FACE OF THE SAID ELEMENTS WHEN THE LATTER ARE ENGAGED, AND A SLIDER COMPRISING A PAIR OF PLATE-LIKE PORTIONS IN CONTACT, RESPECTIVELY, WITH SAID FASTENER ELEMENTS AND SAID LIPS, THE IMPROVEMENT WHICH COMPRISES THE ELASTOMERIC MATERIAL IN THE AREA OF CONTACT WITH SAID SLIDER BEING CHLORINATED WHILE THE INTERENGAGING PORTIONS OF SAID LIPS ARE UNCHLORINATED. 